1. Field of the Invention
The present invention relates to a display device, more particularly to a display device having a large screen and capable of repairing a disconnection defect of a wiring to drive a display.
2. Description of the Related Art
In a display device in which pixel electrodes are arranged in a matrix shape, a line width between the wirings formed on a substrate is narrowed based on a higher-definition, of a display panel and a routing length of the wirings formed on the substrate is extended on the display panel as a screen size is increased.
When a disconnection defect is generated in the wiring in the display device, it is not possible to drive the display device to display a pixel at a position distant from a part of the disconnection defect in a direction where a signal is transmitted, which significantly deteriorates a display quality. As a conventionally known construction proposed for dealing with the problem, an example of which is recited in No. H08-171081 of the Publication of the Unexamined Japanese Patent Applications, a preliminary wiring and a preliminary buffer are used to repair a problem (voltage drop) due to the disconnection defect generated in the wiring on the substrate so that the voltage drop is compensated. As the screen of the display panel has a larger size, however, a routing length of the preliminary wiring is increased in the foregoing construction. As a result, a load of the preliminary wiring used for the repair is larger than that of the wiring.
Another conventionally known construction capable of obtaining a display state substantially equal to a display state obtained in the case of normally-routed wirings by solving a driving performance shortage of the preliminary buffer is recited, for example, in No. H11-52928 of the Publication of the Unexamined Japanese Patent Applications.
Based on the foregoing conventional technologies, a charge distributor is installed in the display device as a recent trend in order to reduce power consumption of the display device, an example of which is recited No. 2004-163912 of the Publication of the Unexamined Japanese Patent Applications. According to the construction recited in the publication, the power consumption is reduced in such a manner that charges stored in vertical lines of the display panel are reutilized through changeover of a switch. However, the charge distributing operation is not carried out with respect to the load of the wiring repaired by the preliminary buffer via the preliminary wiring, which is not enough to reduce the power consumption.